A combination container/syringe can be used immediately after being unpackaged without performing troublesome procedures at medical institutions due to the fact that a medicinal solution has been prefilled. In this way, since the combination container/syringe is very convenient, it substantially lightens the workload of people involved in medical service such as physicians and nurses. For this reason, it has been adopted by many medical institutions.
Conventionally, as this combination container/syringe, there is known one that is provided with an outer cylinder, a front stopper and end stopper that are inserted into the outer cylinder from the front and rear end sides and that liquid-tightly seal the medicinal solution that is filled in the outer cylinder, a cylindrical tip that is fitted on the distal end of the outer cylinder from the outer side and in which are provided a bypass chamber that the front stopper enters and a luer tip for attaching the injection needle at the distal end thereof, a finger grip that is fitted from the outer side on the rear end of the outer cylinder, and a plunger rod that is inserted in the outer cylinder from the rear end portion of the outer cylinder and that is coupled to the end stopper (for example, refer to Patent Document 1).
When using this kind of combination container/syringe, by pushing the end stopper into the outer cylinder with the plunger rod, the front stopper moves forward together with the medicinal solution. When the front stopper is pushed out from the outer cylinder and enters into the bypass chamber at the cylindrical tip, the distal end-side seal of the medicinal solution that is sealed between the front stopper and the end stopper is released. Thereby, the medicinal solution flows out from the inside of the outer cylinder into the bypass chamber, and by being guided to the inner surface of the luer tip along the bypass groove that is provided at the inner peripheral surface of the bypass chamber, is guided to the injection needle.